Like the others, I wouldn't jump to "jealousy" because that's a really hard emotion to pick up from a brief facial expression.

She was seeing a new side of you, and listening to you share things with your past T. Chances are, she was busy trying to note as much as she could about the things you said and your behaviour, because it's a more honest you than what she sees in your short visits.

I think if she was feeling that close to you, enough to feel jealousy, that she probably wouldn't have invited your old T to come in for help as she would have used it as an opportunity to further your own bond.